【摘要】 分析、探讨线性-非线性混合约束模态综合法用于土-结构相互作用的动力分析实施方法。据结构存在局部非线性特性,提出对整体结构划分为若干个线性、非线性子结构,对线性子结构只需一步提取特性矩阵并进行方程降阶,而对非线性子结构则逐步提取降阶后的等效特性矩阵。通过组装各子结构达到对整体结构特性矩阵的降阶处理。对非线性子结构凭借在小段时间Δt内利用分段等效线性化手段,通过ANSYS二次开发工具UPFs编辑写成可执行程序文件,并与MATLAB联立计算,实现特性矩阵提取。结果表明,该方法求得结构的各阶频率和动态响应时程曲线与ANSYS直接计算吻合良好。可逐步提取等效弹塑性特性矩阵,为采用变化的特性矩阵对结构进入塑性阶段深层次分析研究提供有效方法。更多还原

【Abstract】 Here,the implementation technique of the linear-nonlinear mixed constraint modal synthesis method was analyzed for soil-structure dynamic interaction. According to the local nonlinear feature,the whole structure was divided into several linear and nonlinear sub-structures. Those linear sub-structures just required only one step to extract the characteristic matrices and reduce equation order,while for nonlinear sub-structures,they needed step by step to extract the reduced order equivalent characteristic matrices. By assembling the above sub-structures,the order of the whole structural characteristic matrix was reduced. For the nonlinear sub-structures,using the piecewise equivalent linearization method within a small time interval Δt,an executable program file to extract the characteristic matrices was edited by means of ANSYS secondary development tools UPFs and the simultaneous computation was done with MATLAB. Results show that the modal frequencies and dynamic response time history curves obtained with the above method agree well with those obtained with ANSYS direct calculation; using this method can extract the equivalent elastic-plastic feature matrices step by step,and it provides an effective tool for further studying the plastic phase dynamic analysis of structures with time-varying characteristic matrices.更多还原